ABSTRACT
BACKGROUND: Anterior femoral cortical impingement and perforation are known risks of cephalomedullary nailing. The incidence of and risk factors for these findings have not been fully established in the literature. The purpose of this review was to answer: (1) What is the incidence of anterior femoral cortical impingement and perforation associated with cephalomedullary nailing of proximal femur fractures? (2) How does incidence vary by nail radius of curvature (ROC)? (3) What populations are at increased risk of impingement and perforation? (4) What surgical techniques prevent their occurrence? HYPOTHESIS: Our hypothesis was that impingement would be a relatively common finding following cephalomedullary nailing, and perforation would be much less frequent but still an appreciable risk. Secondarily, nails with a larger ROC would have a higher rate of impingement. PATIENTS AND METHODS: In this systematic review, PubMed, MEDLINE, and Cochrane databases were searched for articles from 1990-2020 written in English using the terms "cephalomedullary nail" or "femoral nail" and "perforation" or "impingement", and similar words. Inclusion criteria were studies discussing the complication of anterior femoral cortical impingement or perforation associated with the use of a cephalomedullary nail. Fourteen studies met inclusion criteria. Rates of anterior femoral cortical impingement or perforation, patient demographics, nail type, and ROC were extracted. Surgical techniques to prevent perforation were qualitatively reviewed. RESULTS: The rate of anterior cortical impingement with long cephalomedullary nails was 17.2% (192/1117 patients) and with short nails was 29.2% (176/602). The rate of anterior cortical perforation with long nails was 1.0% (11/1116) and with short nails was 0% (0/234). Long nails with ROC>150cm showed an impingement rate of 10.9% (62/567) and perforation rate of 1.1% (7/617 patients). Nails with ROC 150cm or 100cm had an impingement rate of 1.1% (1/93) and perforation rate of 0% (0/93). DISCUSSION: Impingement and perforation of the anterior femoral cortex during cephalomedullary nailing are appreciable risks that surgeons should anticipate and avoid, especially in certain populations and with nails with larger ROC. Surgeons may consider use of long nails with ROC 150cm and below, given a nearly 10-fold lower incidence of impingement and no reported perforations. LEVEL OF EVIDENCE: Therapeutic, level IV.
